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Diffstat (limited to 'libraries/Wire/Wire.cpp')
-rw-r--r-- | libraries/Wire/Wire.cpp | 330 |
1 files changed, 0 insertions, 330 deletions
diff --git a/libraries/Wire/Wire.cpp b/libraries/Wire/Wire.cpp deleted file mode 100644 index 7944fcb..0000000 --- a/libraries/Wire/Wire.cpp +++ /dev/null @@ -1,330 +0,0 @@ -/* - TwoWire.cpp - TWI/I2C library for Wiring & Arduino - Copyright (c) 2006 Nicholas Zambetti. All right reserved. - - This library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - This library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with this library; if not, write to the Free Software - Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - - Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts -*/ - -extern "C" { - #include <stdlib.h> - #include <string.h> - #include <inttypes.h> - #include "twi.h" -} - -#include "Wire.h" - -// Initialize Class Variables ////////////////////////////////////////////////// - -uint8_t TwoWire::rxBuffer[BUFFER_LENGTH]; -uint8_t TwoWire::rxBufferIndex = 0; -uint8_t TwoWire::rxBufferLength = 0; - -uint8_t TwoWire::txAddress = 0; -uint8_t TwoWire::txBuffer[BUFFER_LENGTH]; -uint8_t TwoWire::txBufferIndex = 0; -uint8_t TwoWire::txBufferLength = 0; - -uint8_t TwoWire::transmitting = 0; -void (*TwoWire::user_onRequest)(void); -void (*TwoWire::user_onReceive)(int); - -// Constructors //////////////////////////////////////////////////////////////// - -TwoWire::TwoWire() -{ -} - -// Public Methods ////////////////////////////////////////////////////////////// - -void TwoWire::begin(void) -{ - rxBufferIndex = 0; - rxBufferLength = 0; - - txBufferIndex = 0; - txBufferLength = 0; - - twi_init(); -} - -void TwoWire::begin(uint8_t address) -{ - twi_setAddress(address); - twi_attachSlaveTxEvent(onRequestService); - twi_attachSlaveRxEvent(onReceiveService); - begin(); -} - -void TwoWire::begin(int address) -{ - begin((uint8_t)address); -} - -void TwoWire::end(void) -{ - twi_disable(); -} - -void TwoWire::setClock(uint32_t frequency) -{ - TWBR = ((F_CPU / frequency) - 16) / 2; -} - -uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity, uint32_t iaddress, uint8_t isize, uint8_t sendStop) -{ - if (isize > 0) { - // send internal address; this mode allows sending a repeated start to access - // some devices' internal registers. This function is executed by the hardware - // TWI module on other processors (for example Due's TWI_IADR and TWI_MMR registers) - - beginTransmission(address); - - // the maximum size of internal address is 3 bytes - if (isize > 3){ - isize = 3; - } - - // write internal register address - most significant byte first - while (isize-- > 0) - write((uint8_t)(iaddress >> (isize*8))); - endTransmission(false); - } - - // clamp to buffer length - if(quantity > BUFFER_LENGTH){ - quantity = BUFFER_LENGTH; - } - // perform blocking read into buffer - uint8_t read = twi_readFrom(address, rxBuffer, quantity, sendStop); - // set rx buffer iterator vars - rxBufferIndex = 0; - rxBufferLength = read; - - return read; -} - -uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity, uint8_t sendStop) { - return requestFrom((uint8_t)address, (uint8_t)quantity, (uint32_t)0, (uint8_t)0, (uint8_t)sendStop); -} - -uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity) -{ - return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)true); -} - -uint8_t TwoWire::requestFrom(int address, int quantity) -{ - return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)true); -} - -uint8_t TwoWire::requestFrom(int address, int quantity, int sendStop) -{ - return requestFrom((uint8_t)address, (uint8_t)quantity, (uint8_t)sendStop); -} - -void TwoWire::beginTransmission(uint8_t address) -{ - // indicate that we are transmitting - transmitting = 1; - // set address of targeted slave - txAddress = address; - // reset tx buffer iterator vars - txBufferIndex = 0; - txBufferLength = 0; -} - -void TwoWire::beginTransmission(int address) -{ - beginTransmission((uint8_t)address); -} - -// -// Originally, 'endTransmission' was an f(void) function. -// It has been modified to take one parameter indicating -// whether or not a STOP should be performed on the bus. -// Calling endTransmission(false) allows a sketch to -// perform a repeated start. -// -// WARNING: Nothing in the library keeps track of whether -// the bus tenure has been properly ended with a STOP. It -// is very possible to leave the bus in a hung state if -// no call to endTransmission(true) is made. Some I2C -// devices will behave oddly if they do not see a STOP. -// -uint8_t TwoWire::endTransmission(uint8_t sendStop) -{ - // transmit buffer (blocking) - uint8_t ret = twi_writeTo(txAddress, txBuffer, txBufferLength, 1, sendStop); - // reset tx buffer iterator vars - txBufferIndex = 0; - txBufferLength = 0; - // indicate that we are done transmitting - transmitting = 0; - return ret; -} - -// This provides backwards compatibility with the original -// definition, and expected behaviour, of endTransmission -// -uint8_t TwoWire::endTransmission(void) -{ - return endTransmission(true); -} - -// must be called in: -// slave tx event callback -// or after beginTransmission(address) -size_t TwoWire::write(uint8_t data) -{ - if(transmitting){ - // in master transmitter mode - // don't bother if buffer is full - if(txBufferLength >= BUFFER_LENGTH){ - setWriteError(); - return 0; - } - // put byte in tx buffer - txBuffer[txBufferIndex] = data; - ++txBufferIndex; - // update amount in buffer - txBufferLength = txBufferIndex; - }else{ - // in slave send mode - // reply to master - twi_transmit(&data, 1); - } - return 1; -} - -// must be called in: -// slave tx event callback -// or after beginTransmission(address) -size_t TwoWire::write(const uint8_t *data, size_t quantity) -{ - if(transmitting){ - // in master transmitter mode - for(size_t i = 0; i < quantity; ++i){ - write(data[i]); - } - }else{ - // in slave send mode - // reply to master - twi_transmit(data, quantity); - } - return quantity; -} - -// must be called in: -// slave rx event callback -// or after requestFrom(address, numBytes) -int TwoWire::available(void) -{ - return rxBufferLength - rxBufferIndex; -} - -// must be called in: -// slave rx event callback -// or after requestFrom(address, numBytes) -int TwoWire::read(void) -{ - int value = -1; - - // get each successive byte on each call - if(rxBufferIndex < rxBufferLength){ - value = rxBuffer[rxBufferIndex]; - ++rxBufferIndex; - } - - return value; -} - -// must be called in: -// slave rx event callback -// or after requestFrom(address, numBytes) -int TwoWire::peek(void) -{ - int value = -1; - - if(rxBufferIndex < rxBufferLength){ - value = rxBuffer[rxBufferIndex]; - } - - return value; -} - -void TwoWire::flush(void) -{ - // XXX: to be implemented. -} - -// behind the scenes function that is called when data is received -void TwoWire::onReceiveService(uint8_t* inBytes, int numBytes) -{ - // don't bother if user hasn't registered a callback - if(!user_onReceive){ - return; - } - // don't bother if rx buffer is in use by a master requestFrom() op - // i know this drops data, but it allows for slight stupidity - // meaning, they may not have read all the master requestFrom() data yet - if(rxBufferIndex < rxBufferLength){ - return; - } - // copy twi rx buffer into local read buffer - // this enables new reads to happen in parallel - for(uint8_t i = 0; i < numBytes; ++i){ - rxBuffer[i] = inBytes[i]; - } - // set rx iterator vars - rxBufferIndex = 0; - rxBufferLength = numBytes; - // alert user program - user_onReceive(numBytes); -} - -// behind the scenes function that is called when data is requested -void TwoWire::onRequestService(void) -{ - // don't bother if user hasn't registered a callback - if(!user_onRequest){ - return; - } - // reset tx buffer iterator vars - // !!! this will kill any pending pre-master sendTo() activity - txBufferIndex = 0; - txBufferLength = 0; - // alert user program - user_onRequest(); -} - -// sets function called on slave write -void TwoWire::onReceive( void (*function)(int) ) -{ - user_onReceive = function; -} - -// sets function called on slave read -void TwoWire::onRequest( void (*function)(void) ) -{ - user_onRequest = function; -} - -// Preinstantiate Objects ////////////////////////////////////////////////////// - -TwoWire Wire = TwoWire(); - |